theorem
MathlibNt.SieveTheory.compact_tail_integral
{f : ℝ → ℝ}
{x B : ℝ}
(hcont : ContinuousOn f (Set.Icc x B))
(hzero : ∀ (t : ℝ), B ≤ t → f t = 0)
:
A continuous function vanishing beyond an endpoint has an integrable compact tail.
theorem
MathlibNt.SieveTheory.Lemma132FiniteTailIdentity_exactRecursionThreshold
(N : ℕ)
(x : ℝ)
:
2 ≤ N →
2 + ↑(N % 2) ≤ x →
MeasureTheory.IntegrableOn (fun (t : ℝ) => SuzukiFiniteContinuousLayers.finiteSourceLayer 1 2 (N - 1) (t - 1))
(Set.Ioi x) MeasureTheory.volume ∧ x * SuzukiFiniteContinuousLayers.finiteSourceLayer 1 2 N x = ∫ (t : ℝ) in Set.Ioi x, SuzukiFiniteContinuousLayers.finiteSourceLayer 1 2 (N - 1) (t - 1)
The finite-tail identity at the exact lower threshold used by the recursive
numerator: 2 on even layers and 3 on odd layers.
The weaker hypothesis x ∈ parityDomain 2 N is sufficient on the even branch,
but not on the odd branch: there it only says 1 < x, while the recursive
lower endpoint remains clamped at 3.
theorem
MathlibNt.SieveTheory.Lemma132FiniteTailIdentity_even_parityDomain
(N : ℕ)
(x : ℝ)
(hN : 2 ≤ N)
(hEven : N % 2 = 0)
(hx : x ∈ SuzukiFiniteContinuousLayers.KappaOneModel.parityDomain 2 N)
:
MeasureTheory.IntegrableOn (fun (t : ℝ) => SuzukiFiniteContinuousLayers.finiteSourceLayer 1 2 (N - 1) (t - 1))
(Set.Ioi x) MeasureTheory.volume ∧ x * SuzukiFiniteContinuousLayers.finiteSourceLayer 1 2 N x = ∫ (t : ℝ) in Set.Ioi x, SuzukiFiniteContinuousLayers.finiteSourceLayer 1 2 (N - 1) (t - 1)
On the even parity branch, Suzuki's exact parity-domain lower endpoint is already the exact recursion threshold.